### kingofnumbers's blog

By kingofnumbers, 8 years ago,

I need help to solved this intersting problem link .

• +8

 » 3 years ago, # |   0 if you now know how to solve it then please help .
•  » » 3 years ago, # ^ | ← Rev. 4 →   -8 not sure at all but this might work:First, let's work on finding the # of cool numbers <= X, for a given X (then we can get the answer by computing that for B and A-1).For a fixed X, we can get the # of cool numbers with a dp[digit][sum1][sum2][alreadyless_bit]digit will be the position of the digit we're trying, We will go from most significative to least. sum1 and sum2 are the sums of the two sets. alreadyless_bit tells if we are already strictly less than X, if so, the new digit can be any digit, otherwise, it has to be between 0 and the respective X's digit.This counts the cool numbers but it might count each one many times, I don't know if you can avoid that hehe
 » 20 months ago, # |   +8 Did you solve this problem later.. ? If yes can you share your idea?
 » 9 days ago, # |   0 Can someone help in this question
 » 9 days ago, # | ← Rev. 2 →   +7 I might be wrong, but how about... Spoiler...submitting some "solutions" close to the source size limit? ;)
•  » » 9 days ago, # ^ |   +5 I couldn't think of any solution. I know above idea proposed by lmn0x4F seems to be good but couldn't find a way to for overcounting issue.Can you provide some hint?
•  » » » 8 days ago, # ^ |   +5 I viciously precomputed answers for blocks of size 200000 and then solved naively for the remainders. You might want to have a fast naive solver (i.e., $O(d)$ instead of $O(d^2)$ knapsack). Keep in mind the 50K source size limit.
•  » » » » 7 days ago, # ^ |   0 Thanks a lot for sharing your approach